No Cooling Option on Nest Thermostat After AC install

[FazzleDazzle]

I had my AC installed at my new house today and when I attempted to test it, I wasn't able to set my Nest Thermostat to Cool Mode. It doesn't show on the device or on my Google Home app. My friend next door has this option on his Google Home app. I assume it has to do with my wiring but I don't have a picture of how my wired were set up on the old thermostat. I have the old thermostat but when I put the wires into the Google Wire input tool it just tells me it should be compatible. I don't have a y1 input, just a Y. The old thermostat is called Home-Stat. The wire inputs are RH, RC, G, W, S2, C/S1, Y (Conventional)

[Patrick_Caezza]

Do you have a picture of the original thermostat's wiring?

[FazzleDazzle]

Unfortunately not 😞  I looked through all my photos and so I’m not sure. I will try to compare with a neighbour to see how theirs is wired. Am I stuck otherwise? 

[Patrick_Caezza]

Look in the furnace/air handler and take a picture of the terminal block on the control board there.

You can't go by how your neighbors are wired.

[FazzleDazzle]

Ok. I will send a picture tonight. Thanks 

[FazzleDazzle]

Here is a picture I just took. Hopefully you can see what you need to see. HVAC guy keeps saying he connected the yellow wire to the AC ( not sure what that means). I can email the photo or upload on computer if it’s too blurry here.

 

[Patrick_Caezza]

Thank you, but I can't read the labels for the terminal block. I'm going to guess they are labeled (from top-down) Y, G, R, C, W. Let me know if I guess correctly

I'm seeing three different cables.

Green cable  with Red, Wht, Yel, Blu, and Grn wires

Brown cable with Red and Wht wires

Yellow cable with Blu, Red, Grn, Wht wires

I'm guessing the green cable goes to the thermostat as it is connected to the Y, G, R, C, and W terminals

The brown cable goes to a humidifier or similar since it's connected to the W and C terminals

 I have no clue what the yellow cable goes to with it being connected to the G and R terminals and the Wht and Grn wires going off of the picture.

The Wht and Red wires connected to the Y and C terminals go to the outdoor unit.

Have you tried doing a Factory Reset and setting it up again from scratch?

The green cable for the thermostat is wired just like you have it at the Nest thermostat and it should work..

THe only thing I can think of is the Yellow Cable is coming into play some how.

[FazzleDazzle]

You’re right. That’s the order of the labels on the terminal block. 
I have an air exchanger unit that uses some of these wires but I’d be guessing which ones. 
One thing that throws me off is that there’s a point where the green and yellow wires connect in my basement. See picture. You can see that the white wires are not connected
I’ll try factory reset tonight. 

[FazzleDazzle]

 

[Patrick_Caezza]

Which cable goes to the thermostat and which goes to the furnace/air handler?

There is more going on in your system than I can figure out, you might want to bring an HVAC tech in.

The best thing I can tell you is to start tracing out where each cable goes and how they are connected and then draw it out on paper.

[Ryan_G]

Hi FazzleDazzle,

Thanks for the update.

It is great to hear that you were able to get your thermostat to recognize the cooling wire. Let us know how it goes after your HVAC guy checks your system.

Thanks for always helping us, Patrick_Caezza.

Best regards,

Ryan

[Bellymom]

How do you find that box on the furnace I have no idea how that was found

[FazzleDazzle]

So it seems that I was able to get my thermostat to recognize and offer the cooling option. Success! But now my AC unit won’t actually go on. My HVAC guy is coming to fix today. Thank you for your help! 

[Frijolero]

did you figure out the problem

[FazzleDazzle]

Not really. It was combination of wiring and the breaker being faulty. 

[Ryan_G]

Hey everyone,

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have. 

Best regards,

Ryan

[aatienza]

Hey folks,

Chiming in to ensure everything is covered here. How's your device? Let us know if you still need help, and the community will be happy to lend a hand.

Thanks,

Archie

[aatienza]

Hey folks,

Just checking in to make sure that you've seen our responses. Please let me know if you have other questions or concerns as I will be locking this in 24 hours if I won't hear back from you again. Feel free to start a new thread and we'll be happy to help.

Thanks,

Archie